Strap seal and system

ABSTRACT

A plastic seal and system is configured for sealing to first and second confronting courses of plastic strap material. The seal includes a body having first and second opposing walls. The first wall has a sealing element formed therein that is bounded by a first wall opening, and the second wall has a sealing element formed therein that is bounded by a second wall opening. The sealing element is connected to the body by one or more frangible connectors. The body defines a central opening for receiving the first and second confronting courses of strap material generally parallel and adjacent to their respective opposing walls. The first sealing element is sealed to the first course of strap material and the second seal element is sealed to the second course of strap material to form a strap seal. A tool and a method for positioning and tensioning a plastic strap around a load are also disclosed.

BACKGROUND OF THE INVENTION

The present invention pertains to an improved tool for tightening a strap around an object or load and adhering the strap onto itself. More particularly, the present invention is directed to a novel plastic or polymeric strap seal and system for sealing plastic or polymeric strap.

Strapping tools are well-known in the art. These tools come in a wide variety of types, from fully manual tools to automatic, table-top tools. These tools are specifically designed for use with either metal (steel) strapping or plastic/polymeric type strapping. The strap is wrapped around the load, tensioned and then overlying courses of the strap material are sealed to one another. The strap courses can be sealed directly to one another (as when plastic strap is welded to itself and metal strap is notched to itself), or they can be joined by a third element such as a seal. The seal, which can be a grit seal for metal or a crimp seal for plastic, is wrapped around the courses of strap and crimped (and deformed) onto the strap.

Although these strapping and seal configurations function well, there are a number of drawbacks. First, metal strap requires corner protectors for certain goods to prevent damage to the goods. Moreover, the metal strap is typically fabricated from steel that can rust which can subsequently stain the goods. For example, stainless steel or plastic pipe can be stained by rust from the strap.

With respect to plastic strap, in order to weld the strap to itself (as in a typical plastic strap application), a tool having a relatively large foot (e.g., footprint) must rest on the goods to be strapped. The large foot is needed to provide an arrangement for tensioning the strap and to provide a base for the strap to be compressed and vibrated or welded. This arrangement is not practicable with small diameter loads because the tool foot cannot rest on the load.

As to the use of a separate element seal the seal is formed from metal as well, and can rust, which can stain the goods. Moreover, when the seal is crimped over the strap, the portions of the seal that compress onto the strap to create the seal are relatively narrow lines that extend along the length of the seal along the sides of the seal. As such, the sealing area is quite small relative to the size of the seal.

Accordingly, there is a need for a plastic strap seal and system that uses a separate seal element to effect a high strength, high integrity seal. Desirably, such a seal and system can be used with small diameter packages, eliminating the need for a large-foot strapping tool. More desirably, such a seal and system is formed from non-staining and non-marring materials. Most desirably, such a seal and system facilitates the preparation and application of the seal to the strap and the strap to the package.

BRIEF SUMMARY OF THE INVENTION

A strapping seal and system uses a separate seal element to effect a high strength, high integrity seal to the strapping on a load. The present seal and system can be used with small diameter packages without the need for a large-foot tool resting on the load to tension the strap. Such a seal is formed from a plastic or polymer and is thus non-staining and non-marring. The seal and system facilitate the preparation and application of the seal to the strap by permitting the “pre-application” of the seal to one end of the strap and thus facilitates application of the strap to the package.

The seal includes a body having first and second opposing, walls. The walls each have a sealing element formed therein that is bounded by a wall opening. Preferably, the sealing elements are formed as disks (and the openings are round openings) that are connected to their respective walls by frangible bridge-like connectors.

The body defines a central opening for receiving the first and second confronting courses of strap material generally parallel and adjacent to their respective opposing walls. The first sealing element is sealed to the first course of strap material and the second seal element is sealed to the second course of strap material to effect a strap seal. In this manner, the sealing elements are bound by the openings in their respective walls. This prevents the strap (and the sealing elements sealed thereto) from being pulled from the seal body.

In a present seal, the first and second opposing walls define a single longitudinal opening through the seal for receiving the first and second courses of strap material in adjacent, confronting relation to one another. Alternately, the seal can include a dividing wall extending through the central opening, generally parallel to the first and second opposing walls. In this embodiment, the first course of strap material is disposed between dividing wall and the first wall and the second course of strap material is disposed between the dividing wall and the second wall. In the single longitudinal opening embodiment, the seal is configured (e.g., the sealing elements are sufficiently thick) so that even with just the first course of strap material sealed with the first sealing element, the combined strap and element cannot be removed from the seal because the strap/seal combination is thicker than the width of the longitudinal opening.

The seal includes opposing side edges between and connecting the first and second opposing walls to one another. To facilitate the strapping operation, the seal can include longitudinal securing flanges extending along the side edges.

In one embodiment, the sealing disks are in opposing, aligned relation to one another and are located centrally disposed in their respective walls.

A tool for forming the seal includes a body, a holding member for securely holding the plastic seal and a sealing head configured to engage one of the sealing elements and to move the sealing element relative to its respective adjacent course of strap seal to fuse the sealing element to the strap material. In a present tool, the sealing element is rotated to fuse it to the strap.

The holding member can be formed as a jaw. The jaw can be a stationary jaw, or preferably a movable jaw. The movable jaw can a pair of jaw elements pivotable toward and away from one another to secure and release the seal.

The tool can trigger actuated and can include a linkage linked to the trigger to movable the jaw into engagement with the seal.

The tool can be fabricated as a portable tool. Such a potable tool can be powered, for example, by mechanical, electro-mechanical or pneumatic means. A presently anticipated tool is battery powered.

Optionally, the tool can include a tensioner for drawing tension in the strap prior to forming a seal between the second course of strap and the seal.

A method for positioning and tensioning a plastic strap around a load includes the steps of providing a length of strap material, inserting the strap material into a seal to form a first course of strap material, sealing the first course of strap material to the seal, positioning the strap around the load, inserting the strap material into the seal to form a second course of strap material, tensioning the strap around the load and sealing the second course of strap material to the seal.

The step of positioning the strap around the load can be carried out prior to the step of inserting the strap material into the seal to form a second course of strap material. Alternately, the step of inserting the strap material into the seal to form a second course of strap material can be carried out prior to the step of positioning the strap around the load.

The steps of sealing the first and second courses of strap material to the seal can include fusing the strap and seal to one another.

These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:

FIG. 1 is a perspective view of one embodiment of a strap seal embodying the principles of the present invention;

FIG. 2 is a top view of the seal of FIG. 1;

FIG. 3 is a cross-sectional view of the seal taken along line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view of the seal taken along line 4-4 of FIG. 2;

FIG. 5 is an enlarged, partial view of the seal as indicated in FIG. 3;

FIG. 6 is a perspective view of the seal as secured in a sealing tool and having a length of strap material fitted in the seal;

FIG. 7A is a partial cross-sectional view of the seal with the tool head moving toward the sealing element;

FIG. 7B is a partial cross-sectional view of the seal with the tool head in contact with the sealing element;

FIG. 7C is a partial cross-sectional view of the seal with the tool head in contact with and rotating the sealing element to seal the element to the strap;

FIG. 8 illustrates the severing of the strap following the sealing of the first course of strap material and the seal;

FIG. 9 illustrates wrapping the strap around a load following sealing the first course of strap material;

FIG. 10 illustrates positioning the second course of strap material around the load and in the seal;

FIG. 11 illustrates positioning the tool on the seal;

FIG. 12 illustrates a push tensioner used to tension the seal;

FIG. 13 illustrates sealing the seal and the second course of strap material;

FIGS. 14A-14C illustrate forming the seal between the seal and the second course of strap material;

FIG. 15 illustrates the completed seal;

FIG. 16 is a side view of an alternate strapping tool having a movable jaw;

FIG. 17 is a perspective view of the tool with the seal positioned for securing by the seal, a portion of the outer case of the tool being removed to show portion of the jaw assembly;

FIG. 18 is a side view of the tool as shown in FIG. 17;

FIG. 19 is a side view of the tool of FIG. 18 in an actuated state, with the jaw elements closed on the seal and the sealing head (although not shown) moving toward the sealing element for engagement;

FIG. 20 is an enlarged, partial view of the tool as seen in FIG. 19 with the seal secured by the jaw elements and the sealing head in contact with the sealing element;

FIG. 21 is a bottom perspective view of the tool and seal as seen in FIG. 20;

FIGS. 22 and 23 are alternate embodiments of the seal;

FIG. 24 illustrates a tool that incorporates the strapping tool and the push tensioner into a single unit;

FIG. 25 is a side view illustrating a small diameter load or bundle having a strap seal in accordance with the present invention; and

FIG. 26 illustrates a portable or cart mounted sealer system embodying principles of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.

It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention”, relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.

Referring now to the figures and in particular to FIG. 1 there is shown a strap seal 10 embodying the principles of the present invention. The seal is configured for use with strap S (see FIG. 6) of a conventional plastic or polymeric type.

The seal 10 is of type not previously known. It is a separately formed element (that is, separately formed from the strap S), that is applied to the strap S in first and second operations to seal the seal 10 to first and second courses S₁, S₂ of strap.

The seal 10 includes a body 12 defining first and second opposing walls 14, 16 connected to one another by opposing sides or edges 18, 20 that essentially define a sleeve. The walls 14, 16 and edges 18, 20 are generally rigid and the walls 14, 16 have a predetermined thickness t₁₄, t₁₆. A present seal body 12 is a rectangular sleeve having a single central sleeve opening 22. The height h₂₂ of the seal opening 22 is about equal to (or slightly greater than) two times the thickness t_(S) of the strap S so that the two courses of strap S₁, S₂ fit within the opening 22 without being overly snug or overly loose.

Sealing elements 24, 26, are formed in each of the opposing walls 14, 16. In a present seal 10, the sealing elements 24, 26 are disks that are disposed within circular openings 28, 30 in their respective walls 14, 16. The disks 24, 26 are connected to their walls 14, 16 by one or more frangible connectors 32. Alternately, the disks 24, 26 can be formed as discrete elements and fitted or secured (e.g., snapped) into their respective openings. The connectors 32 are bridge-like elements that provide secure, yet easily severable connection of the sealing elements 24, 26 to the walls 14, 16. The sealing elements 24, 26, like the walls 14, 16, have a predetermined thickness t₂₄, t₂₆. In a present seal 10, the element thicknesses t₂₄, t₂₆ that is about the same or greater than the thickness of the walls t₁₄, t₁₆.

The seal 10 is configured such that one of the sealing elements 24 is sealed to the first course of strap S₁ adjacent to that element 24 and the other sealing element 26 is sealed to the other or second course of strap S₂, which is adjacent to that sealing element 26. This forms, essentially, two opposing strap-and-element locking members 34, 36 that, because of the presence of one another, and because of the interference of the elements 24, 26 with their respective walls 14, 16 at their respective openings 28, 30, secure the strap-and-element locking members 34, 36 in place within the seal 10.

In a present seal 10, the seal elements 24, 26 are “welded” or otherwise fused to their adjacent straps S₁, S₂. Welding is accomplished by rotating the disk 24, 26 relative to the stationary strap S₁, S₂, thus fusing the materials to one another. A present disk 24, 26 includes a central opening 38 that provides for better control of the disk 24, 26 as it is rotated.

The illustrated seal 10 further includes a pair of gripping flanges 40 extending longitudinally along the opposing sides 18, 20.

One tool 100 for carrying out the sealing function is illustrated in FIGS. 6, 8 and 11-13. The tool 100 includes a body 102, a sealer head 104, a handle (not shown), one or more drives 108 and a jaw assembly 110. The sealer head 104 is configured to reciprocate; that is, the sealer head 104 moves toward and away from the seal 10 (as indicated by the double headed arrow at 112) when it is secured in the tool 110, and is also configured to rotate to effect the weld between the sealing element 24, 26 and the strap S₁, S₂. A present sealer head 104 includes a projecting finger 114 that engages and inserts into the disk central opening 30 to maintain the head 104 and disk 24, 26 (axes) centered on one another or collinear to prevent wobble of the disk 24, 26. The head 104 can also include other elements (such as teeth 116) to maintain engagement of the head 104 and sealing element 24, 26.

The drive or drives 108 include both a reciprocating drive (to move the head 104 into and out of contact with the sealing element 24, 26) and a rotating drive to form the seal. The drives 108 can be any of a number of types of drives, including but not limited to electric, mechanical (for the reciprocating motion), electro-mechanical, pneumatic or the like. A presently anticipated tool 100 includes a battery powered electric motor for the rotational movement (see FIGS. 16-21). This will provide maximum flexibility in use and handling. Of course, all such other types of drives are within the scope of the present invention.

The tool 100 that is shown variously in FIGS. 6-13 includes a stationary jaw 110 having opposing engaging portions 118, 120 into which the seal body 12 is inserted. A stop 122 in the jaw 110 prevents over-insertion of the seal 10 and is configured to position the seal 10 such that the sealing element 24, 26 is aligned with (directly below) the sealing head 104.

An alternate tool 200, as seen in FIGS. 16-21 and in part in FIG. 24, includes a body 202 having the sealing element drives (the reciprocating drive 204 and the rotating drive 206) mounted therein. The movable jaw assembly 208 is configured to pivot the jaw elements 210 212, inward to hold or secure the seal 10 and to pivot outward to release the seal 10. When secured, the sealing head 214 can move downwardly to engage and rotate the sealing disks 24, 26 to form the seals.

The jaw assembly 208 is actuated with the reciprocating drive 204 which is actuated by the tool trigger 216 (e.g., pulling the tool trigger 216). A first drive bar 218 is operably connected to the trigger 216. A linkage 220 connects the first drive bar 218 and the jaw elements 210, 212. The first drive bar 218 is linked to a pair of drive plates 222 by a T-bar 224. The T-bar 224 is linked to the first drive bar 218 by a pin 226 and notched slot 228 arrangement. In this manner, movement of the first drive bar 218, relative to the jaw elements 210, 212, can be translated to linear movement of the T-bar 224.

The drive plates 222 are mounted to either side of the jaw elements 210, 212 and are connected to each other by connecting pins 230. The plates 222 thus reciprocate (e.g., move up and down) on either side of the jaw elements 210, 212, and move together as they are maintained connected by the connecting pins 230. The plates 222 each have a pair of arcuate slots 232 that extend outwardly toward the free end 234 of the plates 222 (away from the T-bar 224 connection), and form jaw element tracks.

The jaw elements 210, 212 are mounted to the assembly 208 in a floating arrangement. The jaw elements 210, 212 are pivotally mounted to link fingers 236. The link fingers 236 include an elongated slot 238 through which the plate connecting pins 230 extend. In this manner, the fingers 236 are retained in the assembly by the connecting pins 230, but are allowed, to some extent, to move longitudinally along with the jaw elements 210, 212. The jaw elements 210, 212 include outwardly projecting pins 240 that extend into the slots 232 (the jaw element tracks) to guide the pivotal movement of the jaw elements 210, 212.

Referring to FIGS. 18 and 21, it can be seen that with the trigger 216 in the neutral state (not pulled), the first drive bar 218, T-bar 224 and drive plates 222 are directed toward the tool body 202. In this state, the jaw pins 240 are in the lower, outwardly directed portion of the pin tracks 232. This pivots the jaw elements 210, 212 outwardly to open the jaw 208.

As the trigger 216 is pulled (as seen in FIGS. 19 and 20), the first drive bar 218, T-bar 224 and drive plates 222 move downward. Because the jaw elements 210, 212 are maintained relatively stationary (in a longitudinal direction), the jaw pins 240 ride in the pin track 232 inward, toward one another. This urges the jaw elements 210, 212 inward to secure or hold the seal 10. As seen in FIG. 19, the jaw elements 210, 212 have channels 242 formed in the inner surfaces 244 that engage the longitudinal gripping flanges 40 on the seal 10. It will be appreciated that the jaw assembly 208 could be in a normally open condition (as seen in FIG. 16) or a normally closed condition in which depressing (squeezing) the trigger 216 would result in the jaw assembly 208 opening and, when the trigger 216 is released, the jaw assembly 208 would close.

With the seal 10 secured in the jaw 208, and an end of the strap S (or a first course S₁ of strap) inserted into the central opening 22 (or sleeve) such that the strap S is positioned adjacent one of the walls 14 with the sealing element 24 overlying the strap S₁, the reciprocating drive 204 is actuated (by pulling trigger 216) to bring the head 214 into contact with the disk 24. The rotational drive 206 is then actuated to seal the disk 24 to the strap S₁. The head 214 can be configured with an engaging or frictional element 246 that prevents the head 214 from slipping relative to the disk 24. In this manner, the disk 24 is fully engaged by and rotated with the head 214. Friction that develops between the disk 24 and the strap S₁ serves to heat and fuse the disk 24 to the strap S₁.

The seal (as indicated at 44) that is formed between the disk 24 and the strap S₁ is substantially contained at the disk/strap juncture 42 (localized to the friction-subjected areas of the disk 24 and the strap S₁) and does not extend, to any appreciable extent, “beyond” this juncture. And, because the seal 44 extends over substantially the entirety of the disk/strap juncture 42, the seal 44 has been found to be extremely strong. In fact it has been found that the seal 44 is at least as strong as conventional vibrating strap seals. This forms a section of strap material with a seal at one end and an (opposite) free end 46 (see, e.g., FIG. 10).

Following the forming of the first seal (first seal of the element 24 and the strap S₁), the strap S is encircled around the load L, and the free end 46 of the strap S is passed through the seal central opening 22, between the strap S₁ (that is now sealed at the seal end) and opposite wall 16 of the seal 10 to establish the second course of strap material S₂. The strap free end 46 is then pulled or tensioned relative to the seal 10. Upon achieving a desired tension in the strap S, the sealer tool 200 is actuated, the sealer head 214 reciprocates down into contact with the sealing disk 26 and rotates to seal the disk 26 with the second course of strap material S₂. The seal 44 is formed much the same way; that is, the friction that develops between the disk 26 and the strap S₂ serves to heat and fuse the disk 26 to the strap S₂ and the seal 44 between the disk 26 and the strap S₂ is substantially contained at the disk/strap juncture 42, localized to the friction-subjected areas of the disk 26 and the strap S₂.

It will be appreciated that each seal 44 is discrete unto itself. That is, the seal 44 formed between the disk 24 and the first course of strap material S₁, and the seal 44 formed between the disk 26 and the second course of strap material S₂ are each limited to the sealing disk 24 or 26 and the strap S₁ or S₂ adjacent to it and the straps S₁, S₂ are not sealed to one another. In fact, each seal/strap formation 24/S₁ and 26/S₂ can move relative to the seal body 12, within the limits of the disk 24, 26 moving within the disk opening 28, 30. Thus, the seals 44 are secured in the body 12 by virtue of interference between the disk 24, 26 and that portion of the wall 14, 16 that defines the disk opening 28, 30. This, it has been found, provides high integrity, high strength seal.

As with any sealing system, the present system requires that the strap S is tensioned around the load L, prior to sealing, to maintain the load L in a bundled configuration. Moreover, unlike known plastic strappers the seal 10 system can be used to strap packages L having relatively small diameters d_(L). This is due to the seal 10 being sealed to the strap S and by virtue of the seal 10 providing a surface 48 (e.g., the front of the seal 10, see FIGS. 1 and 2) against which the strap S can be tensioned. Unlike known plastic strapping systems, the present seal 10 system can take advantage of a “push” tensioner (as indicated generally at 300 in FIGS. 12-13), rather than a conventional tensioner.

In use of a push tensioner 300, after the strap S is looped around the load L, a forward portion 301 of the tensioner tool 300 rests against the front surface 48 of the seal 10 and pulls tension in the strap S (by passing the strap S through the nip 302 of a pair of wheels 304, 306). Essentially, the tool 300 (at the forward portion 301) pushes against the front 48 of the seal 10 while the strap S is being pulled by rotation of the wheels 304, 306—hence a push tensioner. In this manner, the tensioner 300 need not rest on the load L, but need only have a sufficiently sized surface, such as the surface 308, to rest against the seal front 48 against which to “push” the seal 10. This is in complete contrast to known plastic strapping tools which require a fairly large foot to rest on the load to effect a conventional tensioning cycle and vibrationally formed seal. Of course, the present system can be used with a conventional type of tensioner, however, it is not necessary.

It will also be appreciated that the sealer tool 100, 200 and tensioner 300 functions can be configured into a single tool 400, perhaps such as that illustrated in FIG. 24, to minimize the number of tools needed to strap a load L. Such a tool 400 can be configured in a compact, easy handled and operated tool. Such a tool could use pneumatic, electric, electro-mechanical or any other type of drive system. A presently contemplated tool 400 is a battery powered tool to facilitate portable use.

It is also contemplated that a system can be configured, such as that illustrated in FIG. 26, having a centralized (possibly stand or cart mounted) unit 500 that dispenses strap material S, inserts the material through the seal 10 and forms the first course S₁ seal of the seal 10 (sealing disk 24) to the strap S₁. Such a system 500 can be configured to dispense a predetermined length of strap S with the seal 10 affixed to one end, to facilitate rapid and efficient strapping operations.

Alternate embodiments of the seal are illustrated in FIGS. 22 and 23. In a first alternate embodiment 610, a dividing wall 612 extends through the central opening 622, generally parallel to the first and second opposing walls 614, 616. In this embodiment, the first course of strap material is disposed between dividing wall 612 and the first wall 614 and the second course of strap material is disposed between the dividing wall 612 and the second wall 616. The sealing elements 624 (the second one not shown) are aligned with one another. In another embodiment 710, the sealing elements 724, 726 are offset from one another.

All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically do so within the text of this disclosure.

In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.

From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims. 

1-23. (canceled)
 24. A method for positioning and tensioning a plastic strap around a load, comprising the steps of: providing a length of strap material; inserting the strap material into a seal to form a first course of strap material; sealing the first course of strap material to the seal; positioning the strap around the load; inserting the strap material into the seal to form a second course of strap material; tensioning the strap around the load; and sealing the second course of strap material to the seal.
 25. The method in accordance with claim 24 wherein the step of positioning the strap around the load is carried out prior to the step of inserting the strap material into the seal to form a second course of strap material.
 26. The method in accordance with claim 24 wherein the step of inserting the strap material into the seal to form a second course of strap material is carried out prior to the step of positioning the strap around the load.
 27. The method in accordance with claim 24 wherein the steps of sealing the first and second courses of strap material to the seal include fusing the strap and seal to one another.
 28. The method in accordance with claim 27 wherein the seal includes first and second sealing elements and wherein the first and second sealing element are fused to the first and second courses of strap material, respectively. 29-31. (canceled) 